The present invention relates to a novel lubricative, oily, cross-linked resin composition, more particularly to an oily, cross-linked resin composition having an excellent heat-resistance, wear-resistance and lubricity.
It is well known that in order to endow the lubricity and wear-resistance to a frictinal sliding surface in a bearing or a control cable, various sleeves of synthetic resins are provided on the sliding surface of the bearing, or liners or covering layers of synthetic resins similar to the sleeves are provided on the sliding surface of the control cable. For example, the control cable such as pull-cable, push-cable or rotatatory cable, which is employed to operate brake, clutch, accelerator, speedometer or the like, consists essentially of a flexible conduit and an inner cable which is a single wire, or which is formed by stranding several wires. Such a control cable can remotely control a working device connected to the one end of the inner cable by push-pull or rotation of the other end of the inner cable. In that case, it is necessary to minimize friction and wear caused between the conduit and the inner cable as much as possible in order to smoothly carry out the above-mentioned operations of the inner cable in the control cable.
As a conventional method, there are methods that the liner of the synthetic resin is interposed between the conduit and the inner cable, that the covering layer of the synthetic resin is provided on the inner cable as mentioned above, and further that a lubricating oil is filled between the conduit and the inner cable. However, these methods are unsatisfied in the lubricity and the wear-resistance of the inner cable, and then cannot endure in a long period of use.
In order to overcome these drawbacks, it is recently suggested that the lubricating oil such us silicone oil is permeated into a polyethylene powder or pellet which gives the liner or covering layer by an extruder. However, in such a method, the lubricating oil is slightly contained in an amount of 5% by weight against the polyethylene powder or pellet, whereby the liner or covering layer obtained still has problems in the lubricity and the wear-resistance. Furthermore, because polyethylene, for example, high density polyethylene, can be used only within low temperature range (less than about 80.degree. C.), the liner or covering layer obtained is inferior at mechanical property in high temperature.
Also, polytetrafluoroethylene and polyacetal are frequently employed as a liner or covering layer material. These are high expensive, and further are unsatisfied in the lubricity and the wear-resistance. That is to say, polytetrafluoroethylene is inferior in the wear-resistance, and polyacetal is inferior in the lubricity.